src/glsl/ir_reader.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include "ir_reader.h"
  25 #include "glsl_parser_extras.h"
  26 #include "glsl_types.h"
  27 #include "s_expression.h"
  28
  29 const static bool debug = false;
  30
  31 namespace {
  32
  33 class ir_reader {
  34 public:
  35    ir_reader(_mesa_glsl_parse_state *);
  36
  37    void read(exec_list *instructions, const char *src, bool scan_for_protos);
  38
  39 private:
  40    void *mem_ctx;
  41    _mesa_glsl_parse_state *state;
  42
  43    void ir_read_error(s_expression *, const char *fmt, ...);
  44
  45    const glsl_type *read_type(s_expression *);
  46
  47    void scan_for_prototypes(exec_list *, s_expression *);
  48    ir_function *read_function(s_expression *, bool skip_body);
  49    void read_function_sig(ir_function *, s_expression *, bool skip_body);
  50
  51    void read_instructions(exec_list *, s_expression *, ir_loop *);
  52    ir_instruction *read_instruction(s_expression *, ir_loop *);
  53    ir_variable *read_declaration(s_expression *);
  54    ir_if *read_if(s_expression *, ir_loop *);
  55    ir_loop *read_loop(s_expression *);
  56    ir_call *read_call(s_expression *);
  57    ir_return *read_return(s_expression *);
  58    ir_rvalue *read_rvalue(s_expression *);
  59    ir_assignment *read_assignment(s_expression *);
  60    ir_expression *read_expression(s_expression *);
  61    ir_swizzle *read_swizzle(s_expression *);
  62    ir_constant *read_constant(s_expression *);
  63    ir_texture *read_texture(s_expression *);
  64    ir_emit_vertex *read_emit_vertex(s_expression *);
  65    ir_end_primitive *read_end_primitive(s_expression *);
  66
  67    ir_dereference *read_dereference(s_expression *);
  68    ir_dereference_variable *read_var_ref(s_expression *);
  69 };
  70
  71 } /* anonymous namespace */
  72
  73 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  74 {
  75    this->mem_ctx = state;
  76 }
  77
  78 void
  79 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  80                    const char *src, bool scan_for_protos)
  81 {
  82    ir_reader r(state);
  83    r.read(instructions, src, scan_for_protos);
  84 }
  85
  86 void
  87 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  88 {
  89    void *sx_mem_ctx = ralloc_context(NULL);
  90    s_expression *expr = s_expression::read_expression(sx_mem_ctx, src);
  91    if (expr == NULL) {
  92       ir_read_error(NULL, "couldn't parse S-Expression.");
  93       return;
  94    }
  95
  96    if (scan_for_protos) {
  97       scan_for_prototypes(instructions, expr);
  98       if (state->error)
  99          return;
 100    }
 101
 102    read_instructions(instructions, expr, NULL);
 103    ralloc_free(sx_mem_ctx);
 104
 105    if (debug)
 106       validate_ir_tree(instructions);
 107 }
 108
 109 void
 110 ir_reader::ir_read_error(s_expression *expr, const char *fmt, ...)
 111 {
 112    va_list ap;
 113
 114    state->error = true;
 115
 116    if (state->current_function != NULL)
 117       ralloc_asprintf_append(&state->info_log, "In function %s:\n",
 118                              state->current_function->function_name());
 119    ralloc_strcat(&state->info_log, "error: ");
 120
 121    va_start(ap, fmt);
 122    ralloc_vasprintf_append(&state->info_log, fmt, ap);
 123    va_end(ap);
 124    ralloc_strcat(&state->info_log, "\n");
 125
 126    if (expr != NULL) {
 127       ralloc_strcat(&state->info_log, "...in this context:\n   ");
 128       expr->print();
 129       ralloc_strcat(&state->info_log, "\n\n");
 130    }
 131 }
 132
 133 const glsl_type *
 134 ir_reader::read_type(s_expression *expr)
 135 {
 136    s_expression *s_base_type;
 137    s_int *s_size;
 138
 139    s_pattern pat[] = { "array", s_base_type, s_size };
 140    if (MATCH(expr, pat)) {
 141       const glsl_type *base_type = read_type(s_base_type);
 142       if (base_type == NULL) {
 143          ir_read_error(NULL, "when reading base type of array type");
 144          return NULL;
 145       }
 146
 147       return glsl_type::get_array_instance(base_type, s_size->value());
 148    }
 149
 150    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 151    if (type_sym == NULL) {
 152       ir_read_error(expr, "expected <type>");
 153       return NULL;
 154    }
 155
 156    const glsl_type *type = state->symbols->get_type(type_sym->value());
 157    if (type == NULL)
 158       ir_read_error(expr, "invalid type: %s", type_sym->value());
 159
 160    return type;
 161 }
 162
 163
 164 void
 165 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 166 {
 167    s_list *list = SX_AS_LIST(expr);
 168    if (list == NULL) {
 169       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 170       return;
 171    }
 172
 173    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 174       s_list *sub = SX_AS_LIST(it.get());
 175       if (sub == NULL)
 176          continue; // not a (function ...); ignore it.
 177
 178       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 179       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 180          continue; // not a (function ...); ignore it.
 181
 182       ir_function *f = read_function(sub, true);
 183       if (f == NULL)
 184          return;
 185       instructions->push_tail(f);
 186    }
 187 }
 188
 189 ir_function *
 190 ir_reader::read_function(s_expression *expr, bool skip_body)
 191 {
 192    bool added = false;
 193    s_symbol *name;
 194
 195    s_pattern pat[] = { "function", name };
 196    if (!PARTIAL_MATCH(expr, pat)) {
 197       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 198       return NULL;
 199    }
 200
 201    ir_function *f = state->symbols->get_function(name->value());
 202    if (f == NULL) {
 203       f = new(mem_ctx) ir_function(name->value());
 204       added = state->symbols->add_function(f);
 205       assert(added);
 206    }
 207
 208    exec_list_iterator it = ((s_list *) expr)->subexpressions.iterator();
 209    it.next(); // skip "function" tag
 210    it.next(); // skip function name
 211    for (/* nothing */; it.has_next(); it.next()) {
 212       s_expression *s_sig = (s_expression *) it.get();
 213       read_function_sig(f, s_sig, skip_body);
 214    }
 215    return added ? f : NULL;
 216 }
 217
 218 static bool
 219 always_available(const _mesa_glsl_parse_state *)
 220 {
 221    return true;
 222 }
 223
 224 void
 225 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 226 {
 227    s_expression *type_expr;
 228    s_list *paramlist;
 229    s_list *body_list;
 230
 231    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 232    if (!MATCH(expr, pat)) {
 233       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 234                           "(<instruction> ...))");
 235       return;
 236    }
 237
 238    const glsl_type *return_type = read_type(type_expr);
 239    if (return_type == NULL)
 240       return;
 241
 242    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 243    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 244       ir_read_error(paramlist, "Expected (parameters ...)");
 245       return;
 246    }
 247
 248    // Read the parameters list into a temporary place.
 249    exec_list hir_parameters;
 250    state->symbols->push_scope();
 251
 252    exec_list_iterator it = paramlist->subexpressions.iterator();
 253    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 254       ir_variable *var = read_declaration((s_expression *) it.get());
 255       if (var == NULL)
 256          return;
 257
 258       hir_parameters.push_tail(var);
 259    }
 260
 261    ir_function_signature *sig =
 262       f->exact_matching_signature(state, &hir_parameters);
 263    if (sig == NULL && skip_body) {
 264       /* If scanning for prototypes, generate a new signature. */
 265       /* ir_reader doesn't know what languages support a given built-in, so
 266        * just say that they're always available.  For now, other mechanisms
 267        * guarantee the right built-ins are available.
 268        */
 269       sig = new(mem_ctx) ir_function_signature(return_type, always_available);
 270       f->add_signature(sig);
 271    } else if (sig != NULL) {
 272       const char *badvar = sig->qualifiers_match(&hir_parameters);
 273       if (badvar != NULL) {
 274          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 275                        "don't match prototype", f->name, badvar);
 276          return;
 277       }
 278
 279       if (sig->return_type != return_type) {
 280          ir_read_error(expr, "function `%s' return type doesn't "
 281                        "match prototype", f->name);
 282          return;
 283       }
 284    } else {
 285       /* No prototype for this body exists - skip it. */
 286       state->symbols->pop_scope();
 287       return;
 288    }
 289    assert(sig != NULL);
 290
 291    sig->replace_parameters(&hir_parameters);
 292
 293    if (!skip_body && !body_list->subexpressions.is_empty()) {
 294       if (sig->is_defined) {
 295          ir_read_error(expr, "function %s redefined", f->name);
 296          return;
 297       }
 298       state->current_function = sig;
 299       read_instructions(&sig->body, body_list, NULL);
 300       state->current_function = NULL;
 301       sig->is_defined = true;
 302    }
 303
 304    state->symbols->pop_scope();
 305 }
 306
 307 void
 308 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 309                              ir_loop *loop_ctx)
 310 {
 311    // Read in a list of instructions
 312    s_list *list = SX_AS_LIST(expr);
 313    if (list == NULL) {
 314       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 315       return;
 316    }
 317
 318    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 319       s_expression *sub = (s_expression*) it.get();
 320       ir_instruction *ir = read_instruction(sub, loop_ctx);
 321       if (ir != NULL) {
 322          /* Global variable declarations should be moved to the top, before
 323           * any functions that might use them.  Functions are added to the
 324           * instruction stream when scanning for prototypes, so without this
 325           * hack, they always appear before variable declarations.
 326           */
 327          if (state->current_function == NULL && ir->as_variable() != NULL)
 328             instructions->push_head(ir);
 329          else
 330             instructions->push_tail(ir);
 331       }
 332    }
 333 }
 334
 335
 336 ir_instruction *
 337 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 338 {
 339    s_symbol *symbol = SX_AS_SYMBOL(expr);
 340    if (symbol != NULL) {
 341       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 342          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 343       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 344          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 345    }
 346
 347    s_list *list = SX_AS_LIST(expr);
 348    if (list == NULL || list->subexpressions.is_empty()) {
 349       ir_read_error(expr, "Invalid instruction.\n");
 350       return NULL;
 351    }
 352
 353    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 354    if (tag == NULL) {
 355       ir_read_error(expr, "expected instruction tag");
 356       return NULL;
 357    }
 358
 359    ir_instruction *inst = NULL;
 360    if (strcmp(tag->value(), "declare") == 0) {
 361       inst = read_declaration(list);
 362    } else if (strcmp(tag->value(), "assign") == 0) {
 363       inst = read_assignment(list);
 364    } else if (strcmp(tag->value(), "if") == 0) {
 365       inst = read_if(list, loop_ctx);
 366    } else if (strcmp(tag->value(), "loop") == 0) {
 367       inst = read_loop(list);
 368    } else if (strcmp(tag->value(), "call") == 0) {
 369       inst = read_call(list);
 370    } else if (strcmp(tag->value(), "return") == 0) {
 371       inst = read_return(list);
 372    } else if (strcmp(tag->value(), "function") == 0) {
 373       inst = read_function(list, false);
 374    } else if (strcmp(tag->value(), "emit-vertex") == 0) {
 375       inst = read_emit_vertex(list);
 376    } else if (strcmp(tag->value(), "end-primitive") == 0) {
 377       inst = read_end_primitive(list);
 378    } else {
 379       inst = read_rvalue(list);
 380       if (inst == NULL)
 381          ir_read_error(NULL, "when reading instruction");
 382    }
 383    return inst;
 384 }
 385
 386 ir_variable *
 387 ir_reader::read_declaration(s_expression *expr)
 388 {
 389    s_list *s_quals;
 390    s_expression *s_type;
 391    s_symbol *s_name;
 392
 393    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 394    if (!MATCH(expr, pat)) {
 395       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 396       return NULL;
 397    }
 398
 399    const glsl_type *type = read_type(s_type);
 400    if (type == NULL)
 401       return NULL;
 402
 403    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 404                                                ir_var_auto);
 405
 406    foreach_iter(exec_list_iterator, it, s_quals->subexpressions) {
 407       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 408       if (qualifier == NULL) {
 409          ir_read_error(expr, "qualifier list must contain only symbols");
 410          return NULL;
 411       }
 412
 413       // FINISHME: Check for duplicate/conflicting qualifiers.
 414       if (strcmp(qualifier->value(), "centroid") == 0) {
 415          var->data.centroid = 1;
 416       } else if (strcmp(qualifier->value(), "sample") == 0) {
 417          var->data.sample = 1;
 418       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 419          var->data.invariant = 1;
 420       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 421          var->data.mode = ir_var_uniform;
 422       } else if (strcmp(qualifier->value(), "auto") == 0) {
 423          var->data.mode = ir_var_auto;
 424       } else if (strcmp(qualifier->value(), "in") == 0) {
 425          var->data.mode = ir_var_function_in;
 426       } else if (strcmp(qualifier->value(), "shader_in") == 0) {
 427          var->data.mode = ir_var_shader_in;
 428       } else if (strcmp(qualifier->value(), "const_in") == 0) {
 429          var->data.mode = ir_var_const_in;
 430       } else if (strcmp(qualifier->value(), "out") == 0) {
 431          var->data.mode = ir_var_function_out;
 432       } else if (strcmp(qualifier->value(), "shader_out") == 0) {
 433          var->data.mode = ir_var_shader_out;
 434       } else if (strcmp(qualifier->value(), "inout") == 0) {
 435          var->data.mode = ir_var_function_inout;
 436       } else if (strcmp(qualifier->value(), "temporary") == 0) {
 437          var->data.mode = ir_var_temporary;
 438       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 439          var->data.interpolation = INTERP_QUALIFIER_SMOOTH;
 440       } else if (strcmp(qualifier->value(), "flat") == 0) {
 441          var->data.interpolation = INTERP_QUALIFIER_FLAT;
 442       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 443          var->data.interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
 444       } else {
 445          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 446          return NULL;
 447       }
 448    }
 449
 450    // Add the variable to the symbol table
 451    state->symbols->add_variable(var);
 452
 453    return var;
 454 }
 455
 456
 457 ir_if *
 458 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 459 {
 460    s_expression *s_cond;
 461    s_expression *s_then;
 462    s_expression *s_else;
 463
 464    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 465    if (!MATCH(expr, pat)) {
 466       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 467       return NULL;
 468    }
 469
 470    ir_rvalue *condition = read_rvalue(s_cond);
 471    if (condition == NULL) {
 472       ir_read_error(NULL, "when reading condition of (if ...)");
 473       return NULL;
 474    }
 475
 476    ir_if *iff = new(mem_ctx) ir_if(condition);
 477
 478    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 479    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 480    if (state->error) {
 481       delete iff;
 482       iff = NULL;
 483    }
 484    return iff;
 485 }
 486
 487
 488 ir_loop *
 489 ir_reader::read_loop(s_expression *expr)
 490 {
 491    s_expression *s_body;
 492
 493    s_pattern loop_pat[] = { "loop", s_body };
 494    if (!MATCH(expr, loop_pat)) {
 495       ir_read_error(expr, "expected (loop <body>)");
 496       return NULL;
 497    }
 498
 499    ir_loop *loop = new(mem_ctx) ir_loop;
 500
 501    read_instructions(&loop->body_instructions, s_body, loop);
 502    if (state->error) {
 503       delete loop;
 504       loop = NULL;
 505    }
 506    return loop;
 507 }
 508
 509
 510 ir_return *
 511 ir_reader::read_return(s_expression *expr)
 512 {
 513    s_expression *s_retval;
 514
 515    s_pattern return_value_pat[] = { "return", s_retval};
 516    s_pattern return_void_pat[] = { "return" };
 517    if (MATCH(expr, return_value_pat)) {
 518       ir_rvalue *retval = read_rvalue(s_retval);
 519       if (retval == NULL) {
 520          ir_read_error(NULL, "when reading return value");
 521          return NULL;
 522       }
 523       return new(mem_ctx) ir_return(retval);
 524    } else if (MATCH(expr, return_void_pat)) {
 525       return new(mem_ctx) ir_return;
 526    } else {
 527       ir_read_error(expr, "expected (return <rvalue>) or (return)");
 528       return NULL;
 529    }
 530 }
 531
 532
 533 ir_rvalue *
 534 ir_reader::read_rvalue(s_expression *expr)
 535 {
 536    s_list *list = SX_AS_LIST(expr);
 537    if (list == NULL || list->subexpressions.is_empty())
 538       return NULL;
 539
 540    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 541    if (tag == NULL) {
 542       ir_read_error(expr, "expected rvalue tag");
 543       return NULL;
 544    }
 545
 546    ir_rvalue *rvalue = read_dereference(list);
 547    if (rvalue != NULL || state->error)
 548       return rvalue;
 549    else if (strcmp(tag->value(), "swiz") == 0) {
 550       rvalue = read_swizzle(list);
 551    } else if (strcmp(tag->value(), "expression") == 0) {
 552       rvalue = read_expression(list);
 553    } else if (strcmp(tag->value(), "constant") == 0) {
 554       rvalue = read_constant(list);
 555    } else {
 556       rvalue = read_texture(list);
 557       if (rvalue == NULL && !state->error)
 558          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 559    }
 560
 561    return rvalue;
 562 }
 563
 564 ir_assignment *
 565 ir_reader::read_assignment(s_expression *expr)
 566 {
 567    s_expression *cond_expr = NULL;
 568    s_expression *lhs_expr, *rhs_expr;
 569    s_list       *mask_list;
 570
 571    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 572    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 573    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 574       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 575                           "<lhs> <rhs>)");
 576       return NULL;
 577    }
 578
 579    ir_rvalue *condition = NULL;
 580    if (cond_expr != NULL) {
 581       condition = read_rvalue(cond_expr);
 582       if (condition == NULL) {
 583          ir_read_error(NULL, "when reading condition of assignment");
 584          return NULL;
 585       }
 586    }
 587
 588    unsigned mask = 0;
 589
 590    s_symbol *mask_symbol;
 591    s_pattern mask_pat[] = { mask_symbol };
 592    if (MATCH(mask_list, mask_pat)) {
 593       const char *mask_str = mask_symbol->value();
 594       unsigned mask_length = strlen(mask_str);
 595       if (mask_length > 4) {
 596          ir_read_error(expr, "invalid write mask: %s", mask_str);
 597          return NULL;
 598       }
 599
 600       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 601
 602       for (unsigned i = 0; i < mask_length; i++) {
 603          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 604             ir_read_error(expr, "write mask contains invalid character: %c",
 605                           mask_str[i]);
 606             return NULL;
 607          }
 608          mask |= 1 << idx_map[mask_str[i] - 'w'];
 609       }
 610    } else if (!mask_list->subexpressions.is_empty()) {
 611       ir_read_error(mask_list, "expected () or (<write mask>)");
 612       return NULL;
 613    }
 614
 615    ir_dereference *lhs = read_dereference(lhs_expr);
 616    if (lhs == NULL) {
 617       ir_read_error(NULL, "when reading left-hand side of assignment");
 618       return NULL;
 619    }
 620
 621    ir_rvalue *rhs = read_rvalue(rhs_expr);
 622    if (rhs == NULL) {
 623       ir_read_error(NULL, "when reading right-hand side of assignment");
 624       return NULL;
 625    }
 626
 627    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 628       ir_read_error(expr, "non-zero write mask required.");
 629       return NULL;
 630    }
 631
 632    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 633 }
 634
 635 ir_call *
 636 ir_reader::read_call(s_expression *expr)
 637 {
 638    s_symbol *name;
 639    s_list *params;
 640    s_list *s_return = NULL;
 641
 642    ir_dereference_variable *return_deref = NULL;
 643
 644    s_pattern void_pat[] = { "call", name, params };
 645    s_pattern non_void_pat[] = { "call", name, s_return, params };
 646    if (MATCH(expr, non_void_pat)) {
 647       return_deref = read_var_ref(s_return);
 648       if (return_deref == NULL) {
 649          ir_read_error(s_return, "when reading a call's return storage");
 650          return NULL;
 651       }
 652    } else if (!MATCH(expr, void_pat)) {
 653       ir_read_error(expr, "expected (call <name> [<deref>] (<param> ...))");
 654       return NULL;
 655    }
 656
 657    exec_list parameters;
 658
 659    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 660       s_expression *expr = (s_expression*) it.get();
 661       ir_rvalue *param = read_rvalue(expr);
 662       if (param == NULL) {
 663          ir_read_error(expr, "when reading parameter to function call");
 664          return NULL;
 665       }
 666       parameters.push_tail(param);
 667    }
 668
 669    ir_function *f = state->symbols->get_function(name->value());
 670    if (f == NULL) {
 671       ir_read_error(expr, "found call to undefined function %s",
 672                     name->value());
 673       return NULL;
 674    }
 675
 676    ir_function_signature *callee = f->matching_signature(state, &parameters);
 677    if (callee == NULL) {
 678       ir_read_error(expr, "couldn't find matching signature for function "
 679                     "%s", name->value());
 680       return NULL;
 681    }
 682
 683    if (callee->return_type == glsl_type::void_type && return_deref) {
 684       ir_read_error(expr, "call has return value storage but void type");
 685       return NULL;
 686    } else if (callee->return_type != glsl_type::void_type && !return_deref) {
 687       ir_read_error(expr, "call has non-void type but no return value storage");
 688       return NULL;
 689    }
 690
 691    return new(mem_ctx) ir_call(callee, return_deref, &parameters);
 692 }
 693
 694 ir_expression *
 695 ir_reader::read_expression(s_expression *expr)
 696 {
 697    s_expression *s_type;
 698    s_symbol *s_op;
 699    s_expression *s_arg[4] = {NULL};
 700
 701    s_pattern pat[] = { "expression", s_type, s_op, s_arg[0] };
 702    if (!PARTIAL_MATCH(expr, pat)) {
 703       ir_read_error(expr, "expected (expression <type> <operator> "
 704                           "<operand> [<operand>] [<operand>] [<operand>])");
 705       return NULL;
 706    }
 707    s_arg[1] = (s_expression *) s_arg[0]->next; // may be tail sentinel
 708    s_arg[2] = (s_expression *) s_arg[1]->next; // may be tail sentinel or NULL
 709    if (s_arg[2])
 710       s_arg[3] = (s_expression *) s_arg[2]->next; // may be tail sentinel or NULL
 711
 712    const glsl_type *type = read_type(s_type);
 713    if (type == NULL)
 714       return NULL;
 715
 716    /* Read the operator */
 717    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 718    if (op == (ir_expression_operation) -1) {
 719       ir_read_error(expr, "invalid operator: %s", s_op->value());
 720       return NULL;
 721    }
 722
 723    int num_operands = -3; /* skip "expression" <type> <operation> */
 724    foreach_list(n, &((s_list *) expr)->subexpressions)
 725       ++num_operands;
 726
 727    int expected_operands = ir_expression::get_num_operands(op);
 728    if (num_operands != expected_operands) {
 729       ir_read_error(expr, "found %d expression operands, expected %d",
 730                     num_operands, expected_operands);
 731       return NULL;
 732    }
 733
 734    ir_rvalue *arg[4] = {NULL};
 735    for (int i = 0; i < num_operands; i++) {
 736       arg[i] = read_rvalue(s_arg[i]);
 737       if (arg[i] == NULL) {
 738          ir_read_error(NULL, "when reading operand #%d of %s", i, s_op->value());
 739          return NULL;
 740       }
 741    }
 742
 743    return new(mem_ctx) ir_expression(op, type, arg[0], arg[1], arg[2], arg[3]);
 744 }
 745
 746 ir_swizzle *
 747 ir_reader::read_swizzle(s_expression *expr)
 748 {
 749    s_symbol *swiz;
 750    s_expression *sub;
 751
 752    s_pattern pat[] = { "swiz", swiz, sub };
 753    if (!MATCH(expr, pat)) {
 754       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 755       return NULL;
 756    }
 757
 758    if (strlen(swiz->value()) > 4) {
 759       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 760       return NULL;
 761    }
 762
 763    ir_rvalue *rvalue = read_rvalue(sub);
 764    if (rvalue == NULL)
 765       return NULL;
 766
 767    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 768                                        rvalue->type->vector_elements);
 769    if (ir == NULL)
 770       ir_read_error(expr, "invalid swizzle");
 771
 772    return ir;
 773 }
 774
 775 ir_constant *
 776 ir_reader::read_constant(s_expression *expr)
 777 {
 778    s_expression *type_expr;
 779    s_list *values;
 780
 781    s_pattern pat[] = { "constant", type_expr, values };
 782    if (!MATCH(expr, pat)) {
 783       ir_read_error(expr, "expected (constant <type> (...))");
 784       return NULL;
 785    }
 786
 787    const glsl_type *type = read_type(type_expr);
 788    if (type == NULL)
 789       return NULL;
 790
 791    if (values == NULL) {
 792       ir_read_error(expr, "expected (constant <type> (...))");
 793       return NULL;
 794    }
 795
 796    if (type->is_array()) {
 797       unsigned elements_supplied = 0;
 798       exec_list elements;
 799       foreach_iter(exec_list_iterator, it, values->subexpressions) {
 800          s_expression *elt = (s_expression *) it.get();
 801          ir_constant *ir_elt = read_constant(elt);
 802          if (ir_elt == NULL)
 803             return NULL;
 804          elements.push_tail(ir_elt);
 805          elements_supplied++;
 806       }
 807
 808       if (elements_supplied != type->length) {
 809          ir_read_error(values, "expected exactly %u array elements, "
 810                        "given %u", type->length, elements_supplied);
 811          return NULL;
 812       }
 813       return new(mem_ctx) ir_constant(type, &elements);
 814    }
 815
 816    ir_constant_data data = { { 0 } };
 817
 818    // Read in list of values (at most 16).
 819    unsigned k = 0;
 820    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 821       if (k >= 16) {
 822          ir_read_error(values, "expected at most 16 numbers");
 823          return NULL;
 824       }
 825
 826       s_expression *expr = (s_expression*) it.get();
 827
 828       if (type->base_type == GLSL_TYPE_FLOAT) {
 829          s_number *value = SX_AS_NUMBER(expr);
 830          if (value == NULL) {
 831             ir_read_error(values, "expected numbers");
 832             return NULL;
 833          }
 834          data.f[k] = value->fvalue();
 835       } else {
 836          s_int *value = SX_AS_INT(expr);
 837          if (value == NULL) {
 838             ir_read_error(values, "expected integers");
 839             return NULL;
 840          }
 841
 842          switch (type->base_type) {
 843          case GLSL_TYPE_UINT: {
 844             data.u[k] = value->value();
 845             break;
 846          }
 847          case GLSL_TYPE_INT: {
 848             data.i[k] = value->value();
 849             break;
 850          }
 851          case GLSL_TYPE_BOOL: {
 852             data.b[k] = value->value();
 853             break;
 854          }
 855          default:
 856             ir_read_error(values, "unsupported constant type");
 857             return NULL;
 858          }
 859       }
 860       ++k;
 861    }
 862    if (k != type->components()) {
 863       ir_read_error(values, "expected %u constant values, found %u",
 864                     type->components(), k);
 865       return NULL;
 866    }
 867
 868    return new(mem_ctx) ir_constant(type, &data);
 869 }
 870
 871 ir_dereference_variable *
 872 ir_reader::read_var_ref(s_expression *expr)
 873 {
 874    s_symbol *s_var;
 875    s_pattern var_pat[] = { "var_ref", s_var };
 876
 877    if (MATCH(expr, var_pat)) {
 878       ir_variable *var = state->symbols->get_variable(s_var->value());
 879       if (var == NULL) {
 880          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 881          return NULL;
 882       }
 883       return new(mem_ctx) ir_dereference_variable(var);
 884    }
 885    return NULL;
 886 }
 887
 888 ir_dereference *
 889 ir_reader::read_dereference(s_expression *expr)
 890 {
 891    s_expression *s_subject;
 892    s_expression *s_index;
 893    s_symbol *s_field;
 894
 895    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 896    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 897
 898    ir_dereference_variable *var_ref = read_var_ref(expr);
 899    if (var_ref != NULL) {
 900       return var_ref;
 901    } else if (MATCH(expr, array_pat)) {
 902       ir_rvalue *subject = read_rvalue(s_subject);
 903       if (subject == NULL) {
 904          ir_read_error(NULL, "when reading the subject of an array_ref");
 905          return NULL;
 906       }
 907
 908       ir_rvalue *idx = read_rvalue(s_index);
 909       if (idx == NULL) {
 910          ir_read_error(NULL, "when reading the index of an array_ref");
 911          return NULL;
 912       }
 913       return new(mem_ctx) ir_dereference_array(subject, idx);
 914    } else if (MATCH(expr, record_pat)) {
 915       ir_rvalue *subject = read_rvalue(s_subject);
 916       if (subject == NULL) {
 917          ir_read_error(NULL, "when reading the subject of a record_ref");
 918          return NULL;
 919       }
 920       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 921    }
 922    return NULL;
 923 }
 924
 925 ir_texture *
 926 ir_reader::read_texture(s_expression *expr)
 927 {
 928    s_symbol *tag = NULL;
 929    s_expression *s_type = NULL;
 930    s_expression *s_sampler = NULL;
 931    s_expression *s_coord = NULL;
 932    s_expression *s_offset = NULL;
 933    s_expression *s_proj = NULL;
 934    s_list *s_shadow = NULL;
 935    s_expression *s_lod = NULL;
 936    s_expression *s_sample_index = NULL;
 937    s_expression *s_component = NULL;
 938
 939    ir_texture_opcode op = ir_tex; /* silence warning */
 940
 941    s_pattern tex_pattern[] =
 942       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
 943    s_pattern lod_pattern[] =
 944       { "lod", s_type, s_sampler, s_coord };
 945    s_pattern txf_pattern[] =
 946       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
 947    s_pattern txf_ms_pattern[] =
 948       { "txf_ms", s_type, s_sampler, s_coord, s_sample_index };
 949    s_pattern txs_pattern[] =
 950       { "txs", s_type, s_sampler, s_lod };
 951    s_pattern tg4_pattern[] =
 952       { "tg4", s_type, s_sampler, s_coord, s_offset, s_component };
 953    s_pattern query_levels_pattern[] =
 954       { "query_levels", s_type, s_sampler };
 955    s_pattern other_pattern[] =
 956       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 957
 958    if (MATCH(expr, lod_pattern)) {
 959       op = ir_lod;
 960    } else if (MATCH(expr, tex_pattern)) {
 961       op = ir_tex;
 962    } else if (MATCH(expr, txf_pattern)) {
 963       op = ir_txf;
 964    } else if (MATCH(expr, txf_ms_pattern)) {
 965       op = ir_txf_ms;
 966    } else if (MATCH(expr, txs_pattern)) {
 967       op = ir_txs;
 968    } else if (MATCH(expr, tg4_pattern)) {
 969       op = ir_tg4;
 970    } else if (MATCH(expr, query_levels_pattern)) {
 971       op = ir_query_levels;
 972    } else if (MATCH(expr, other_pattern)) {
 973       op = ir_texture::get_opcode(tag->value());
 974       if (op == -1)
 975          return NULL;
 976    } else {
 977       ir_read_error(NULL, "unexpected texture pattern %s", tag->value());
 978       return NULL;
 979    }
 980
 981    ir_texture *tex = new(mem_ctx) ir_texture(op);
 982
 983    // Read return type
 984    const glsl_type *type = read_type(s_type);
 985    if (type == NULL) {
 986       ir_read_error(NULL, "when reading type in (%s ...)",
 987                     tex->opcode_string());
 988       return NULL;
 989    }
 990
 991    // Read sampler (must be a deref)
 992    ir_dereference *sampler = read_dereference(s_sampler);
 993    if (sampler == NULL) {
 994       ir_read_error(NULL, "when reading sampler in (%s ...)",
 995                     tex->opcode_string());
 996       return NULL;
 997    }
 998    tex->set_sampler(sampler, type);
 999
1000    if (op != ir_txs) {
1001       // Read coordinate (any rvalue)
1002       tex->coordinate = read_rvalue(s_coord);
1003       if (tex->coordinate == NULL) {
1004          ir_read_error(NULL, "when reading coordinate in (%s ...)",
1005                        tex->opcode_string());
1006          return NULL;
1007       }
1008
1009       if (op != ir_txf_ms && op != ir_lod) {
1010          // Read texel offset - either 0 or an rvalue.
1011          s_int *si_offset = SX_AS_INT(s_offset);
1012          if (si_offset == NULL || si_offset->value() != 0) {
1013             tex->offset = read_rvalue(s_offset);
1014             if (tex->offset == NULL) {
1015                ir_read_error(s_offset, "expected 0 or an expression");
1016                return NULL;
1017             }
1018          }
1019       }
1020    }
1021
1022    if (op != ir_txf && op != ir_txf_ms &&
1023        op != ir_txs && op != ir_lod && op != ir_tg4 &&
1024        op != ir_query_levels) {
1025       s_int *proj_as_int = SX_AS_INT(s_proj);
1026       if (proj_as_int && proj_as_int->value() == 1) {
1027          tex->projector = NULL;
1028       } else {
1029          tex->projector = read_rvalue(s_proj);
1030          if (tex->projector == NULL) {
1031             ir_read_error(NULL, "when reading projective divide in (%s ..)",
1032                           tex->opcode_string());
1033             return NULL;
1034          }
1035       }
1036
1037       if (s_shadow->subexpressions.is_empty()) {
1038          tex->shadow_comparitor = NULL;
1039       } else {
1040          tex->shadow_comparitor = read_rvalue(s_shadow);
1041          if (tex->shadow_comparitor == NULL) {
1042             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
1043                           tex->opcode_string());
1044             return NULL;
1045          }
1046       }
1047    }
1048
1049    switch (op) {
1050    case ir_txb:
1051       tex->lod_info.bias = read_rvalue(s_lod);
1052       if (tex->lod_info.bias == NULL) {
1053          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
1054          return NULL;
1055       }
1056       break;
1057    case ir_txl:
1058    case ir_txf:
1059    case ir_txs:
1060       tex->lod_info.lod = read_rvalue(s_lod);
1061       if (tex->lod_info.lod == NULL) {
1062          ir_read_error(NULL, "when reading LOD in (%s ...)",
1063                        tex->opcode_string());
1064          return NULL;
1065       }
1066       break;
1067    case ir_txf_ms:
1068       tex->lod_info.sample_index = read_rvalue(s_sample_index);
1069       if (tex->lod_info.sample_index == NULL) {
1070          ir_read_error(NULL, "when reading sample_index in (txf_ms ...)");
1071          return NULL;
1072       }
1073       break;
1074    case ir_txd: {
1075       s_expression *s_dx, *s_dy;
1076       s_pattern dxdy_pat[] = { s_dx, s_dy };
1077       if (!MATCH(s_lod, dxdy_pat)) {
1078          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
1079          return NULL;
1080       }
1081       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
1082       if (tex->lod_info.grad.dPdx == NULL) {
1083          ir_read_error(NULL, "when reading dPdx in (txd ...)");
1084          return NULL;
1085       }
1086       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
1087       if (tex->lod_info.grad.dPdy == NULL) {
1088          ir_read_error(NULL, "when reading dPdy in (txd ...)");
1089          return NULL;
1090       }
1091       break;
1092    }
1093    case ir_tg4:
1094       tex->lod_info.component = read_rvalue(s_component);
1095       if (tex->lod_info.component == NULL) {
1096          ir_read_error(NULL, "when reading component in (tg4 ...)");
1097          return NULL;
1098       }
1099       break;
1100    default:
1101       // tex and lod don't have any extra parameters.
1102       break;
1103    };
1104    return tex;
1105 }
1106
1107 ir_emit_vertex *
1108 ir_reader::read_emit_vertex(s_expression *expr)
1109 {
1110    s_pattern pat[] = { "emit-vertex" };
1111
1112    if (MATCH(expr, pat)) {
1113       return new(mem_ctx) ir_emit_vertex();
1114    }
1115    ir_read_error(NULL, "when reading emit-vertex");
1116    return NULL;
1117 }
1118
1119 ir_end_primitive *
1120 ir_reader::read_end_primitive(s_expression *expr)
1121 {
1122    s_pattern pat[] = { "end-primitive" };
1123
1124    if (MATCH(expr, pat)) {
1125       return new(mem_ctx) ir_end_primitive();
1126    }
1127    ir_read_error(NULL, "when reading end-primitive");
1128    return NULL;
1129 }